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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: nativetexan on August 12, 2010, 02:52:47 am

Title: Timing... help.
Post by: nativetexan on August 12, 2010, 02:52:47 am
So, I'm not sure if there is any reason for this, but I can't seem to see the timing line when I shoot the timing light at the balancer. Any ideas?? Am I not seeing it, or is there a reason (i.e. something wrong) for this? I didn't unplug the vaccuum hose, forgot that, but would that cause me to not see the mark at all? I thought maybe it was too far from the timing marker to see it, but it wouldn't start if that were the case... RIGHT???





Title: Re: Timing... help.
Post by: frogman68 on August 12, 2010, 06:00:33 am
What year ?
Might have ESC.
Damper might of spun.
Title: Re: Timing... help.
Post by: Irish_Alley on August 12, 2010, 08:17:34 am
After you give more info LOL but are you saying you don't see it at all or it just doesn't line up when its running.  you can take a reg flashlight and spin the crank till you see the mark and mark the mark with soapstone
Title: Re: Timing... help.
Post by: Lt.Del on August 12, 2010, 12:04:24 pm
get up under the truck and you will see an indention on the balancer and get some white chalk or something and make the mark brighter.

Try to clip the timing gun on different plug wires...may see it then----as mentioned, the balancer could have shifted (it's only rubber surrounded by a metal band.)   plug the vacuum advance hose.   Idle it around 750 rpms.

if the engine is older, it could have the wrong metal tab guage on it.  some are at the 2:00 position, some are at the 12:00 position....it could be the wrong one.

just some ideas
Title: Re: Timing... help.
Post by: 1980c10 on August 12, 2010, 04:56:20 pm
had this problem with my '82- ended that the dist. was installed a tooth off-couldn't get the mark even close to the marks.
Title: Re: Timing... help.
Post by: SUX2BU99 on August 12, 2010, 06:45:08 pm
^ How well did it run with it being a tooth off?
Title: Re: Timing... help.
Post by: Josh454 on August 12, 2010, 07:59:25 pm
Keep in mind there are different locations for the timing tab.  Earlier models have the tab on the side.  Later ones have it on the top.  You might have a early style timing tab with a later model balancer.  Try to put the piston at TDC and see where your timing mark is.
Title: Re: Timing... help.
Post by: 1980c10 on August 12, 2010, 09:56:19 pm
sux2bu-it ran fairly good-timed it by ear and no where near the mark-it would back fire from time to time, completely drivable though- but it ran like new when moved to the correct position.
Title: Re: Timing... help.
Post by: nativetexan on August 13, 2010, 12:17:10 am
Sorry guys. I got a 87 R10 with remanufactured 5.7 SB. I bought a new balancer and a new cover with the gauge on top.  It has the TBI on top. I have it running but can't see the mark when I shoot the light. I will try to use white paint or chalk to see it better. The idle sounds good so I think I have to be close enough to see it a little (right).
Title: Re: Timing... help.
Post by: 1980c10 on August 13, 2010, 12:57:45 am
right. unless you have what I had.
Title: Re: Timing... help.
Post by: Grim 82 on August 18, 2010, 09:00:43 am
If it still has the stock setup for 87 with the TBI, you will need to unplug the bypass wire to time it. With it plugged in at idle it will read 10 or so degrees off, which might be why you can't see the mark.
Title: Re: Timing... help.
Post by: nativetexan on August 20, 2010, 11:26:35 pm
Grim, that is great... But, what is the bypass wire? What does it look like?? ??? ;D
Title: Re: Timing... help.
Post by: bobcooter on August 21, 2010, 06:12:13 am
Just for kicks I would hook the timing light to the #6 cylinder. Someone may have installed a new timing chain / gear 180 degrees out. That would make the #6 cylinder fire when you are thinking the #1 should be firing.
Title: Re: Timing... help.
Post by: Lt.Del on August 21, 2010, 08:53:17 am

Quote
Grim, that is great... But, what is the bypass wire? What does it look like?? 


Hey Texan, that would be your problem then.  The EST bypass needs to be unplugged on computerized trucks to check timing correctly.  These guys on this forum got me straight way back when.... see link.

http://forum.73-87chevytrucks.com/smforum/index.php?topic=9232.15 (http://forum.73-87chevytrucks.com/smforum/index.php?topic=9232.15)
Title: Re: Timing... help.
Post by: nativetexan on August 23, 2010, 12:51:31 pm
 :D MAN!!! You guys are great! That did it. I owe a lot to this site. From beginning to end you guys have helped me through the entire thing. I got the motor timed to 12 behind TDC and it sounds good. I notice the tranny is shifting better too. Maybe that is just the new motor.  ;D

Thanks again...